Hoplitomeryx devosi, Van Der Geer, Alexandra A. E., 2014

Van Der Geer, Alexandra A. E., 2014, Systematic revision of the family Hoplitomerycidae Leinders, 1984 (Artiodactyla: Cervoidea), with the description of a new genus and four new species, Zootaxa 3847 (1), pp. 1-32 : 23-25

Hoplitomeryx devosi sp. nov.

Fig. 7 A–E

Hoplitomeryx matthei Leinders, 1984 — Leinders 1984 (partim): p. 3, fig. 1 [RGM 261.101]; Mazza & Rustioni 2011 (partim): p. 1320 [RGM 261.102].

Hoplitomeryx Leinders, 1984 , ear region type V—Leinders 1984: p. 34, 35, pl. 7 [RGM 261.102].

Hoplitomeryx Leinders, 1984 , ear region type IV—Leinders 1984: p. 31, 35, pl. 6 [RGM 261.096].

Hoplitomeryx Leinders, 1984 , size 1—Van der Geer 2005: p. 330, 333; Van der Geer 2008 (partim): p. 153, 154, fig. 4, 5.

Hoplitomeryx Leinders, 1984 , size 2—Van der Geer 2008 (partim): p. 153, fig. 4.

Hoplitomeryx apulicus Mazza & Rustioni, 2011 — Mazza & Rustioni 2011 (partim): p. 1318, fig. 3, table 2 [RGM 178.445, RGM 178.656, RGM 260.940, RGM 260.966, RGM 425.234].

Hoplitomeryx falcidens Mazza & Rustioni, 2011 — Mazza & Rustioni 2011 (partim): p. 1312, fig. 1, table 2 [RGM 260.941, RGM 261.132, RGM 261.133, RGM 261.447, RGM 425.201].

Hoplitomeryx minutus Mazza & Rustioni, 2011 — Mazza & Rustioni 2011 (partim): p. 1306 [RGM 261.147].

Holotype. Left metacarpal RGM 178.517.

Paratypes. Distal humerus fragment RGM 443.118, radius RGM 260.860, femur RGM 425.314 ( Fig. 5 K), tibia RGM 425.285, astragal RGM 215.234, calcaneum RGM 425.253, posterior second phalanges RGM 261.251 ( Fig. 5 E) and RGM 261.254, pelvis fragment (acetabulum) RGM 261.221, scapula fragment (glenoid) RGM 179.317, mandible RGM 260.940, maxilla fragments RGM 260.941 and RGM 425.201, orbital horn core RGM 260.926.

Referred specimens. See Appendix III, fig. 4I, J and fig. 5I.

Diagnosis. A small-sized, very robust hoplitomerycid. Estimated body mass 21.0 kg. The trochlea of the astragal is either non-parallel sided or almost parallel. The tibia is spirally winded. The fusion between ulna and radius is extensive and includes the part distally of the spatium interosseum. The ulna leaves a trace on the radius in the form of a ridge. The radial facet on the distal radius extends further palmar than the intermedial facet and is deeper and broader than the intermedial facet.

Differential diagnosis. About half the body size of Hoplitomeryx matthei and much more robust.

Derivation of name. Named after John de Vos, former curator of the Dubois collection, Naturalis Biodiversity Center, Leiden for his contribution to the knowledge of fossil insular mammals, in particular insular deer from the Mediterranean islands.

Preservation and deposition. Naturalis Biodiversity Center, Leiden, the Netherlands (formerly Rijksmuseum van Geologie en Mineralogie (RGM)).

Type locality and horizon. Late Miocene (Middle or Late Turolian, MN12-13) fissure filling with code San Giovannino in an abandoned limestone quarry near the farm of San Giovannino south of the provincial road between Poggio Imperiale and Apricena (Province of Foggia, Apulia, Italy).

Studied localities. Fissure fillings with codes Biancone 2, Chirò 2, 2N, 2S, 3, 5, 5A, 7, 10A, 10B, 13, 14, 14B, 18, 26, 27, 28A, 29, 30, D1 and D3, Fina D, H, K and N, Gervasio, Nazario 2A, 3 and 4, Pizzicoli 12, Posticchia 1B, San Giovannino and Trefossi 2A. All localities are located in the north-western portion of the Gargano Peninsula, Apulia, south-eastern Italy. Probable other locality. Fissure filling with code Chirò 24 in the limestone quarry Chirò along the provincial road between Poggio Imperiale and Lessina (Province of Foggia, Apulia, Italy).

Description of the holotype. RGM 178.517 is a complete, left metacarpal with some splinters of the dorsal surface missing. Basically, it corresponds in morphology with that of Cervus and accordingly, the medial facet is larger than the lateral facet on the proximal articulation. It is extremely massive and robust. The crest separating the medial and lateral proximal facet ends in the central fossa and runs more or less parasagitally. The crest forms a pronounced ridge between the two facets. The fossa is situated centrally and the contact area between the lateral and medial facet is minimal. The central fossa is in contact with the palmar surface at which point it is wide. The proximal tubercle for attachment of the carpal ligaments on the dorsal surface is pronounced. The scars for the lateral metacarpals are very pronounced. The palmar groove for the M. interosseus palmaris is clearly present up to about one-third above the distal end of the shaft. The distal end of the metacarpal is straight with the lateral and medial trochlea extending equally far. The dorsal profile of both epicondyls in distal view is cone-shaped.

Measurements. Holotype: maximal length = 94.5 mm, proximal depth (DAPP) = 14.6 mm, proximal width (DTP) = 23.2 mm, distal depth (DAPD) = 12.0 mm, distal width (DTD) = 21.8 mm. For measurements of referred specimens, see Appendix III (linear measurements) and Appendix I and II (body mass estimations).

Remarks. San Giovannino falls within the younger faunal complex (no hamsters; see Introduction) and is one of the youngest localities. Skull fragment RGM 261.102 (ear region type V in Leinders (1984) from the quarry Gervasio) is smaller than the type skull and differs from it by a circular foramen magnum and larger bullae. Based on occipital width, this skull fragment belongs to the smallest species. The configuration of the proximal articulation of the holotype metacarpal was earlier described as morphotype 2 (Van der Geer 2005) and is also observed in the Tokunoshima-type of Cervus astylodon ( Matsumoto, 1926) ( Matsumoto & Otsuka 2000) , Alces alces ( Linnaeus, 1758) and Cervalces Scott, 1885 . Maxillaries RGM 260.941 and RGM 425.201 do not belong to the same individual (contra Mazza & Rustioni 2011), based on their different eruption patterns (this is confirmed by their different hypsodonty index, see above).

Figures

FIGURE 5. Postcranial elements of Hoplitomeryx. A, first posterior phalanx (RGM 425.269; San Giovannino) showing a deerlike morphology: abaxial view; B, same specimen, showing triangular sesamoid facets but no ligament attachment areas: volar view; C, first anterior phalanx (RGM 178.503; San Giovannino): abaxial view; D, same specimen, showing pronounced ligament attachments in the form of ridges but no sesamoid facet: volar view; E, posterior second phalanx (RGM 261.251; San Giovannino): abaxial view; F, anterior second phalanx (RGM 260.937; San Giovannino): axial view; G, third phalanx (RGM 178.683; Trefossi 2 A): abaxial view; H, third phalanx (RGM 260.877; San Giovannino): axial view; I, third phalanx (RGM 261.531; Nazario 4): abaxial view; J, third phalanx (RGM 425.386; Falcone 2 B); K, right femur (RGM 425.314; San Giovannino): anterior view; L, left femur (RGM 425.207; Nazario 4): anterior view; M, right femur (RGM 425.245; San Giovannino): anterior view; N, left patella (RGM 425.246; San Giovannino): anterior (dorsal) view; O, same specimen: lateral view; P, same specimen, showing the hook-like extension at the medial side: inner view.

FIGURE 7. Holotypes of three new Hoplitomeryx species from Gargano, South Italy (Late Miocene; Middle or Late Turolian, MN 12 - 13). A – E Hoplitomeryx devosi sp. n., left metacarpal RGM 178.517; F – I Hoplitomeryx macpheei sp. n., left metacarpal RGM 260.918; J – M Hoplitomeryx kriegsmani sp. n., left metacarpal RGM 178.516. A, F, J proximal view. B, G, K dorsal view. C, H, L palmar view. D, I, M medial view. E distal view. Note that the sideward and backward bending of RGM 178.516 is a post-mortem defect.